/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include "include/webrtc_vad.h"

#include <stdlib.h>

#include "include/vad_core.h"

static const int kInitCheck = 42;
static const int kValidRates[] = {8000, 16000, 32000, 48000};
static const size_t kRatesSize = sizeof(kValidRates) / sizeof(*kValidRates);
static const int kMaxFrameLengthMs = 30;

VadInst *WebRtcVad_Create() {
    VadInstT *self = (VadInstT *) malloc(sizeof(VadInstT));

    self->init_flag = 0;

    return (VadInst *) self;
}

void WebRtcVad_Free(VadInst *handle) {
    free(handle);
}

// TODO(bjornv): Move WebRtcVad_InitCore() code here.
int WebRtcVad_Init(VadInst *handle) {
    // Initialize the core VAD component.
    return WebRtcVad_InitCore((VadInstT *) handle);
}

// TODO(bjornv): Move WebRtcVad_set_mode_core() code here.
int WebRtcVad_set_mode(VadInst *handle, int mode) {
    VadInstT *self = (VadInstT *) handle;

    if (handle == NULL) {
        return -1;
    }
    if (self->init_flag != kInitCheck) {
        return -1;
    }

    return WebRtcVad_set_mode_core(self, mode);
}

int WebRtcVad_Process(VadInst *handle, int fs, const int16_t *audio_frame,
                      size_t frame_length) {
    int vad = -1;
    VadInstT *self = (VadInstT *) handle;

    if (handle == NULL) {
        return -1;
    }

    if (self->init_flag != kInitCheck) {
        return -1;
    }
    if (audio_frame == NULL) {
        return -1;
    }
    if (WebRtcVad_ValidRateAndFrameLength(fs, frame_length) != 0) {
        return -1;
    }

    if (fs == 48000) {
        vad = WebRtcVad_CalcVad48khz(self, audio_frame, frame_length);
    } else if (fs == 32000) {
        vad = WebRtcVad_CalcVad32khz(self, audio_frame, frame_length);
    } else if (fs == 16000) {
        vad = WebRtcVad_CalcVad16khz(self, audio_frame, frame_length);
    } else if (fs == 8000) {
        vad = WebRtcVad_CalcVad8khz(self, audio_frame, frame_length);
    }

    if (vad > 0) {
        vad = 1;
    }
    return vad;
}

int WebRtcVad_ValidRateAndFrameLength(int rate, size_t frame_length) {
    int return_value = -1;
    size_t i;
    int valid_length_ms;
    size_t valid_length;

    // We only allow 10, 20 or 30 ms frames. Loop through valid frame rates and
    // see if we have a matching pair.
    for (i = 0; i < kRatesSize; i++) {
        if (kValidRates[i] == rate) {
            for (valid_length_ms = 10; valid_length_ms <= kMaxFrameLengthMs;
                 valid_length_ms += 10) {
                valid_length = (size_t) (kValidRates[i] / 1000 * valid_length_ms);
                if (frame_length == valid_length) {
                    return_value = 0;
                    break;
                }
            }
            break;
        }
    }

    return return_value;
}
